In a bowl, combine the condensed milk, peanut butter, 1 teaspoon vanilla, salt, cinnamon, nutmeg, 1-1/2 cups chocolate chips and oats; mix well. Spread into an 8-in. square microwave-safe dish; shield corners with small triangles of foil.* Microwave, uncovered, at 50% powder for 10 minutes. Microwave on high for 3-4 minutes or until top springs back when lightly touched. Cool slightly; remove foil. In a microwave-safe bowl, combine milk and the remaining vanilla and chocolate chips. Microwave on high for 30-40 seconds or until chocolate is melted. Stir; spread over bars.